Crystalline epinephrine malonate salt

ABSTRACT

Described herein are epinephrine salts, specifically the epinephrine malonate salt; the epinephrine malonate salt in crystalline form; a pharmaceutical composition comprising epinephrine malonate; a sublingual or buccal pharmaceutical composition comprising epinephrine malonate in crystalline form; and a method for treating a patient comprising administering a pharmaceutical composition of epinephrine malonate in crystalline form.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a divisional of application Ser. No.16/526,286 filed on Jul. 30, 2019, and claims priority to U.S.Provisional Application No. 62/711,936, filed on Jul. 30, 2018, and U.S.Provisional Application No. 62/731,442, filed on Sep. 14, 2018, thedisclosures of which are incorporated herein in their entirety byreference.

FIELD OF THE INVENTION

The invention relates to a novel pharmaceutical salt in crystallineform. More particularly, the invention relates to crystallineepinephrine malonate salt; a pharmaceutical composition comprisingcrystalline epinephrine malonate; and a method for treating a patientcomprising administering a pharmaceutical composition of crystallineepinephrine malonate to a patient.

BACKGROUND OF THE INVENTION

Epinephrine has been used for decades for the treatment of anaphylaxis.In 1958, Bose and co-workers studied different epinephrine salts, suchas epinephrine citrate, focusing on the pharmacological activity of theepinephrine citrate salt. Bose, et al., Observations on thepharmacological activity of different salts of adrenaline, morphine andstrychnine, Indian J Med Res. 46(2):193-8 (March 1958). In 1972, John J.Sciarra and co-workers disclosed a method for the preparation ofepinephrine maleate, epinephrine malate, and epinephrine fumarate. JohnJ. Sciarra, et al., Synthesis and Formulation of Several EpinephrineSalts as an Aerosol Dosage Form, Journal of Pharmaceutical Sciences,61(2), 219-223 (1972). Other salts studied in the literature includeepinephrine hydrochloride and epinephrine bitartrate. T E Peddicord, etal., Stability of high-concentration dopamine hydrochloride,norepinephrine bitartrate, epinephrine hydrochloride, and nitroglycerinin 5% dextrose injection, Am J Health-Syst Pharm. 54, 1417-1419 (1997);M M Rawas-Qalaji, et al., Epinephrine for the Treatment of Anaphylaxis:Do All 40 mg Sublingual Epinephrine Tablet Formulations with Similar InVitro Characteristics Have the Same Bioavailability?, Biopharm. DrugDispos. 27, 427-435 (2006).

SUMMARY OF THE INVENTION

The present invention relates to a novel crystalline epinephrine salt,the epinephrine malonate salt, as well as pharmaceutical compositionscomprising said epinephrine salt, methods for preparing said epinephrinesalt, and methods for treating patients comprising administering saidepinephrine salt to the patient. In a preferred embodiment, thepolymorphic crystalline epinephrine malonate has an x-ray powderdiffraction pattern identified in FIG. 1.

In certain embodiments, a pharmaceutical composition is providedcomprising the epinephrine malonate salt. The pharmaceutical compositioncan be suitable for oral, rectal, intragastrical, topical, intracranial,intranasal, and parenteral administration. In a preferred embodiment,the pharmaceutical composition can be a sublingual or buccal tablet. Thepharmaceutical formulation can comprise a pharmaceutically effectiveamount of epinephrine malonate salt and one or more pharmaceuticallyacceptable excipients, including, e.g., a filler (e.g., microcrystallinecellulose) and a disintegrant (e.g., cross-linked polyvinylpolypyrrolidine or a low-substituted hydroxypropyl cellulose). Incertain embodiments, the pharmaceutical composition can further includea lubricant (e.g., magnesium stearate) and a glidant (e.g., silicondioxide). In certain embodiments the pharmaceutical composition canfurther include a diluent (e.g., mannitol) and/or a pH adjusting agent(e.g., citric acid). The pharmaceutical composition can compriseepinephrine malonate in an amount of 0.3 to 10 mg. The pharmaceuticalcomposition can further comprise a filler in an amount of 20 to 30% byweight and a disintegrant in an amount of 5 to 15% by weight. In certainembodiments, the pharmaceutical composition can disintegrate in lessthan or equal to 30 seconds.

In certain embodiments, a method for preparing said epinephrine malonatesalt is provided. The method can comprise adding malonic acid to asolution of epinephrine base in a solvent (e.g., ethanol). The malonicacid can be added to the solution at a ratio of at least 0.001:1, atleast 0.01:1, at least 1:1, at least 2:1, at least 3:1, at least 5:1, atleast 10:1, at least 25:1, at least 50:1, at least 100:1, at least 500:1relative to epinephrine. The malonic acid can be added to the solutionat a ratio less than or equal to 100:1, less than or equal to 500:1,less than or equal to 100:1, less than or equal to 75:1, less than orequal to 5:1, less than or equal to 3:1, less than or equal to 2:1, lessthan or equal to 1:1. In certain embodiments, the malonic acid can beadded to the solution at a ratio between 0.01:1 and 3:1. In a preferredembodiment, the malonic acid can be added to the solution at a 1:1equivalent relative to epinephrine. The method can comprise stirring thesolution and precipitating the salt out of solution. The method canfurther comprise filtering and drying the precipitate.

In certain embodiments, a method for treating a patient is provided. Themethod comprises administering a pharmaceutically effective amount ofepinephrine malonate to a patient in need of such treatment, includingfor example, a patient inflicted with anaphylaxis.

BRIEF DESCRIPTION OF THE FIGURES

The accompanying figures, which are incorporated herein and form part ofthe specification, illustrate various embodiments of the presentdisclosure and, together with the description, further serve to explainthe principles of the disclosure and to enable a person skilled in thepertinent art to make and use the embodiments disclosed herein.

FIG. 1 shows a proton nuclear magnetic resonance (H NMR) spectrum of anepinephrine malonate salt.

FIG. 2 shows an x-ray powder diffraction (XRPD) spectrum of anepinephrine malonate salt.

FIG. 3 shows a differential scanning calorimetry (DSC) spectrum of anepinephrine malonate salt.

FIG. 4 shows a thermogravimetric analysis of an epinephrine malonatesalt.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates generally to a novel crystallineepinephrine salt. A novel salt of epinephrine, epinephrine malonate, hasbeen found that can be obtained in a crystalline form possessingproperties desirable for pharmaceutical composition, including forexample, sublingual and buccal pharmaceutical compositions.

Before the present invention is described in detail below, it is to beunderstood that this invention is not limited to the particularmethodology, protocols, and reagents described herein as these may vary.It is also to be understood that the terminology used herein is for thepurpose of describing particular embodiments only, and is not intendedto limit the scope of the present invention which will be limited onlyby the appended claims. Unless defined otherwise, all technical andscientific terms used herein have the same meanings as commonlyunderstood by one of ordinary skill in the art to which this inventionbelongs.

The term “about” when used in connection with a numerical value is meantto encompass numerical values within a range having a lower limit thatis 5% smaller than the indicated numerical value and having an upperlimit that is 5% larger than the indicated numerical value.

As used herein, “treat”, “treating” or “treatment” of a disease ordisorder means accomplishing one or more of the following: (a) reducingthe severity and/or duration of the disorder; (b) limiting or preventingdevelopment of symptoms characteristic of the disorder(s) being treated;(c) inhibiting worsening of symptoms characteristic of the disorder(s)being treated; (d) limiting or preventing recurrence of the disorder(s)in patients that have previously had the disorder(s); and (e) limitingor preventing recurrence of symptoms in patients that were previouslysymptomatic for the disorder(s).

A “pharmaceutical composition” according to the invention may be presentin the form of a composition, wherein the different active ingredientsand diluents and/or carriers are admixed with each other, or may takethe form of a combined preparation, where the active ingredients arepresent in partially or totally distinct form. An example for such acombination or combined preparation is a kit-of-parts.

A “therapeutic amount” or “therapeutically effective amount” is anamount of a therapeutic agent sufficient to achieve the intendedpurpose. The effective amount of a given therapeutic agent will varywith factors such as the nature of the agent, the route ofadministration, the size and species of the animal to receive thetherapeutic agent, and the purpose of the administration. The effectiveamount in each individual case may be determined empirically by askilled artisan according to established methods in the art.

As used herein, the terms “patient” or “subject” most preferably refersto a human being. Also included is any mammal or bird that may benefitfrom the compounds described herein. Preferably, a “subject” or“patient” is selected from the group consisting of laboratory animals(e.g. mouse or rat), domestic animals (including e.g. guinea pig,rabbit, chicken, turkey, pig, sheep, goat, camel, cow, horse, donkey,cat, or dog), or other primates including chimpanzees.

“Pharmaceutically acceptable” means generally safe for administration tohumans or animals. Preferably a pharmaceutically acceptable component isone that has been approved by a regulatory agency of the Federal or astate government or listed in the U.S. Pharmacopeia, published by theUnited States Pharmacopeial Convention, Inc., Rockville Md., or othergenerally recognized pharmacopeia for use in animals, and moreparticularly in humans.

In one embodiment, the present invention provides for epinephrinemalonate in a crystalline form having an appearance as a white powder.The epinephrine malonate salt can have a water solubility of 1142.7mg/mL; a pKa of 5.47; and a partition coefficient (log P) of −3.00. Thewater solubility of the epinephrine malonate salt in a crystalline formwas surprisingly substantially higher than the water solubility of otherepinephrine salts. The high water solubility makes the epinephrinemalonate salt particularly well suited for transmucosal delivery of thedrug. A high bioavailability and rapid delivery of the drug areespecially important for epinephrine, which is used to treatanaphylaxis, sometimes in an emergency situation. Additionally, theepinephrine malonate salt is not hygroscopic and can exhibit a favorablestability profile at 7, 14, 30, 60, 90, 120, or 150 days.

The epinephrine malonate salt can be substantially pure. For example,the epinephrine malonate salt can have a purity of greater than or equalto 95%, 96%, 97%, 98%, 99%, 99.5%, 99.6%, 99.7%, 99.8%, or 99.9%.

The epinephrine malonate salt can have a proton nuclear magneticresonance (H NMR) spectrum as illustrated in FIG. 1.

The epinephrine malonate salt can have an x-ray powder diffraction(XRPD) spectrum as illustrated in FIG. 2. As illustrated in FIG. 2, theepinephrine malonate salt can be a polymorph characterized by an x-raypowder spectrum having one or more peaks expressed as 2 theta at about12.1843, 13.4653, 14.2595, 14.6991, 15.8664, 17.3570, 17.9004, 19.5883,20.4659, 21.5801, 22.3908, 22.9301, 23.8776, 24.6585, 25.3418, 26.0105,26.4829, 25.3418, 26.0105, 26.4829, 27.2385, 27.8939, 29.4741, 33.2425,34.2629, 34.8439.

The epinephrine malonate salt can have a differential scanningcalorimetry melting temperature maximum of from about 101° C. to about106° C., preferably from about 102° C. to 104° C., as illustrated inFIG. 3.

In another embodiment, the present invention provides for apharmaceutical composition comprising an epinephrine malonate salt. Thepharmaceutical composition can be suitable for use in oral, rectal,intragastrical, topical, intracranial, intranasal, and parenteraladministration. The pharmaceutical composition can be administered viaany pharmaceutically acceptable dosage form, including solid, semi-solidor liquid dosage forms, such as, for example, tablets, suppositories,pills, capsules, powders, liquids, suspensions, or the like, preferablyin unit dosage forms suitable for single administration of precisedosages, in immediate release or in sustained or controlled releasedosage forms for the prolonged administration of the compound at apredetermined rate. The pharmaceutical composition can include aconventional pharmaceutical carrier or excipient and at least one of thecompounds of the present invention and, in addition, may include othermedicinal agents, pharmaceutical agents, carriers, adjuvants, etc. Thepharmaceutical composition may contain 1 to 95% by weight of theepinephrine malonate salt or more preferably 2 to 50% by weight, 5 to20% by weight, 10 to 20% by weight, or 5 to 15% by weight of theepinephrine malonate salt. Additionally, the pharmaceutical compositioncan exhibit a favorable stability profile at 7, 14, 30 days or more.

In preferred embodiments, the pharmaceutical composition is suitable fortransmucosal administration in the form of a sublingual or buccaltablet. The pharmaceutical composition can comprise a pharmaceuticallyeffective amount of epinephrine malonate salt. In certain embodiments,the pharmaceutical composition suitable for transmucosal administrationin the form of a sublingual or buccal tablet comprises epinephrine freebase in an amount of 0.3 to 10 mg. The pharmaceutical composition canfurther comprise a filler (e.g., microcrystalline cellulose) and adisintegrant (e.g., low-substituted hydroxypropyl cellulose or across-linked polyvinyl polypyrrolidone (crospovidone)). In certainembodiments, the pharmaceutical composition can further include alubricant (e.g., magnesium stearate) and/or a glidant (e.g., silicondioxide). In certain embodiments, the pharmaceutical composition canfurther include a diluent (e.g., mannitol). In certain embodiments, thepharmaceutical composition can further include a pH adjusting agent(e.g., citric acid).

In certain embodiments, the filler to disintegrant ratio can be about9:1, 9.5:0.5, 8:2, 7:3, and 6:4. The pharmaceutical compositions canprovide rapid and complete, or substantially complete, disintegration ofthe buccal or sublingual tablet and can be adjusted to control thedisintegration rate of the tablet. For example, the higher thedisintegrant ratio, the slower the disintegration of the tablet due tolower water penetration of the tablet through capillary action. Incertain embodiments, the buccal or sublingual tablet is capable ofsubstantially or completely disintegrating in less than or equal to 30seconds. In certain embodiments, the pharmaceutical compositions cancomprise one or more fillers, one or more disintegrants, one or morelubricants, and optionally other excipients known in the art. Forexample, the pharmaceutical composition can include one or more ofdiluents, binders, glidants, colorants, flavorants, pH adjusting agents,coating materials and the like, as would have been understood by aperson of ordinary skill in the art.

In some embodiments of the present invention, the pharmaceuticalcomposition comprises a filler, which is microcrystalline cellulose(e.g., Ceolus®-PH-301 or Ceolus KG 802). In other embodiments, thefiller can be one or more of lactose, calcium carbonate, calciumbicarbonate, calcium phosphate, dibasic calcium phosphate, calciumsulfate, calcium silicate, cellulose powders, dextrose, dextrates,dextrans, starches, pregelatinized starches, sucrose, xylitol, lactitol,sorbitol, sodium bicarbonate, sodium chloride, polyethylene glycol, andthe like. In certain embodiments, the pharmaceutical compositioncomprises a filler in an amount of 15-35% by weight, more preferably 20to 30% by weight or 22 to 27% by weight, or most preferably about 25% byweight.

In some embodiments of the present invention, the pharmaceuticalcomposition comprises a disintegrant, which is cross-linked polyvinylpolypyrrolidone (crospovidone) or a low-substituted hydroxypropylcellulose. In other embodiments, the disintegrant can be one or more ofcross-linked celluloses, such as cross-linked sodium carboxymethylcellulose, cross-linked carboxymethyl celluloses, or cross-linkedcroscarmelloses, cross-linked starches such as sodium starch glycolate(e.g., Explotab®), and other cross-linked polymers. In certainembodiments, the pharmaceutical composition comprises a disintigrant inan amount of 2 to 20% by weight, more preferably 5 to 15% by weight or 5to 10% by weight, or most preferably about 6 to 8% by weight.

In some embodiments of the present invention, the pharmaceuticalcomposition comprises a lubricant, which is magnesium stearate, and/or aglidant, which is silicon dioxide. Lubricants are compounds thatprevent, reduce or inhibit adhesion or friction of materials. Glidantsare compounds that improve the flowability of the composition. In otherembodiments, the lubricants and glidants can be one or more of stearicacid, calcium hydroxide, talc, sodium stearyl fumerate, a hydrocarbonsuch as mineral oil, or hydrogenated vegetable oil such as hydrogenatedsoybean oil, higher fatty acids and their alkali-metal and alkalineearth metal salts, such as aluminum, calcium, magnesium, zinc, sodiumstearates, glycerol, waxes, Stearowet®, boric acid, sodium benzoate,sodium acetate, sodium chloride, leucine, a polyethylene glycol (e.g.,PEG-4000) or a methoxypolyethylene glycol, sodium oleate, sodiumbenzoate, glyceryl behenate, polyethylene glycol, magnesium or sodiumlauryl sulfate, colloidal silica, a starch such as corn starch, siliconeoil. In certain embodiments, the pharmaceutical composition comprises alubricant and/or glidant, individually in an amount of 0.1 to 5% byweight, more preferably 0.5 to 4% by weight, or most preferably about 1to 3% by weight.

In some embodiments of the present invention, the pharmaceuticalcomposition includes a diluent, which is mannitol. In other embodiments,the diluent can be lactose, starch, sorbitol, dextrose, tricalciumphosphate, calcium phosphate; anhydrous lactose, spray-dried lactose,pregelatinized starch, hydroxypropylmethyl cellulose,hydroxypropylmethyl cellulose acetate stearate, sucrose-based diluents,monobasic calcium sulfate monohydrate, calcium sulfate dehydrate,calcium lactate trihydrate, dextrates, hydrolyzed cereal solids,amylose, powdered cellulose, calcium carbonate, glycine, kaolin, orsodium chloride. In certain embodiments, the pharmaceutical compositioncomprises a diluent in an amount of 25 to 75% by weight, more preferably35 to 60% by weight, most preferably 45-55% by weight.

In some embodiments of the present invention, the pharmaceuticalcomposition includes a pH adjusting agent, which is citric acid. Inother embodiments, the pH adjusting agent can be boric acid, lacticacid, malic acid, phosphoric acid, sodium phosphate monobasic, ortartaric acid. In certain embodiments, the pharmaceutical compositioncomprises a diluent in an amount of 0.1 to 3% by weight, more preferably0.1 to 2% by weight, or most preferably about 0.1 to 1% by weight.

In certain embodiments, the pharmaceutical formulations can bemanufactured by using direct compression. As would be understood by aperson of ordinary skill in the art, the pharmaceutical formulations canbe designed and prepared as set forth in Keith J. Simons et al.,Fast-Disintegrating Sublingual Tablets: Effect of Epinephrine Load onTablet Characteristics, AAPS PharmSciTech 7(2):E41 (February 2006),which is incorporated herein by reference.

In other embodiments, the present invention provides for a method formanufacturing an epinephrine malonate salt. The method can compriseadding malonic acid to a solution comprising epinephrine and a solvent.The malonic acid can be added to the solution at a ratio of at least0.001:1, at least 0.01:1, at least 1:1, at least 2:1, at least 3:1, atleast 5:1, at least 10:1, at least 25:1, at least 50:1, at least 100:1,at least 500:1 relative to epinephrine. The malonic acid can be added tothe solution at a ratio less than or equal to 100:1, less than or equalto 500:1, less than or equal to 100:1, less than or equal to 75:1, lessthan or equal to 5:1, less than or equal to 3:1, less than or equal to2:1, less than or equal to 1:1. In certain embodiments, the malonic acidcan be added to the solution at a ratio between 0.01:1 and 3:1. In apreferred embodiment, the malonic acid can be added to the solution at a1:1 equivalent relative to epinephrine. The method can further comprisestirring the solution. The method can further comprise adding additionalsolvent to the solution. The method can further comprise stirring thesolution. The method can further comprise precipitating the epinephrinesalt out of solution. The method can further comprise filtering theprecipitate. The method can further comprise drying the precipitate. Inthe method, the solvent can be an alcohol, ketone, or ester. Exemplarysolvents for use with the present invention include methanol, ethanol,n-propanol, iso-propanol, n-butanol, sec-butanol, tert-butanol,n-pentanol, 2-methyl-butanol, 3-methyl-butanol, hexanol, acetone, methylethyl ketone, and ethyl acetate. In a preferred embodiment, the solventis ethanol.

In other embodiments, the present invention provides for a method fortreating a patient. The patient may be a patient suffering from anallergic condition, for example anaphylaxis, asthma, or bronchialasthma. The method comprises administering a pharmaceutically effectiveamount of epinephrine malonate to a patient in need of such treatment,including for example, a patient inflicted with anaphylaxis. The methodcan comprise administering a buccal or sublingual tablet to the patientafflicted with an allergic condition.

The following examples illustrate certain embodiments of the inventionwithout limitation.

EXAMPLES

While various embodiments have been described herein, it should beunderstood that they have been presented by way of example only, and notlimitation. Thus, the breadth and scope of the present disclosure shouldnot be limited by any of the described exemplary embodiments. Moreover,any combination of the described elements in all possible variationsthereof is encompassed by the disclosure unless otherwise indicatedherein or otherwise clearly contradicted by context.

Example 1 Preparation of Epinephrine Malonate Salt

Epinephrine malonate salt was formed using the following method. Malonicacid 2.3 g (1.0 eq) was added to a solution of epinephrine 4 g (1.0 eq)in EtOH (8 mL) at room temperature. The reaction mixture turned to aclear solution after vigorously stirring for 30 mins. EtOH (10 mL) wasadded, and white solid product was precipitated. The mixture was furtherstirred for 10 hours, filtered and dried in vacuum to afford 5.7 g ofthe epinephrine malonate salt (as a white powder).

Example 2 Physical and Chemical Properties of Epinephrine Malonate Salt

The physical and chemical properties of the epinephrine malonate salt ofExample 1 were assessed and compared to other epinephrine salts.

A. Solubility

The solubility of epinephrine malonate salt was assessed and compared toother epinephrine salts. The tests were conducted using Sartoriusbalances (Model SQP), a Thermo HPLC (UltiMate 3000 System, UVWavelength: 205 nm), and Phenomenex Luna columns (5 μm C18 (2), 4.6×250mm). The column temperature was 40° C. and the autosampler temperaturewas room temperature. The injection volume was 5 μL.

Mobile Phase A was prepared by weighing 4.0 g tetramethylammoniumbisulfate (MERYER, Batch No. 77957139) and 1.1 sodium 1-heptasulfonate(Admas-beta, Batch No. P1343755), and transferring the materials to aflask. 2 mL of 0.1 mol/L EDTA solution (Brand: Sinopharm ChemicalReagent Co., Ltd., Batch No. 20150410) was added to the flask and thevolume was adjusted to 950 mL using water. The solution was mixed andadjusted to a pH of 3.5 with 0.1N sodium hydroxide solution (Brand:Enox, Batch No. 20161201). Mobile Phase B was prepared using ethanol.The isocratic elution was used in a proportion of A/B of 85/15. The runtime was 8 minutes.

A standard solution was used comprising 10 mg of the standard dissolvedin 10 mL of water. The test solution solutions were prepared and waterwas added at 25±2° C. Every 5 minutes, the solution was sonicated for 30seconds. The dissolution was observed within 30 minutes to make sure thesolution was saturated. The solution was filtered through a 0.45 ummembrane and the solution was diluted to test. The results of thesolubility study are set forth in Table 1.

TABLE 1 Salt Solubility (mg/mL) epinephrine malonate 1142.7 epinephrinebitartrate 827.0 epinephrine fumarate 38.9 epinephrine hemi sulfate 17.7epinephrine maleate 82.7

B. pH

The pH of epinephrine malonate salt was assessed and compared to otherepinephrine salts. The tests were conducted using Sartorius balances(Model SQP) and a pH meter (Brand: INESA, Model No. PHS-3E). 20 mg ofthe sample was weighed and transferred into a 20 mL volumetric flaskwith the remainder of the volume comprising water. The solution wasmixed. The pH meter was calibrated with pH 4.0 and pH 6.8 standardbuffer solutions at 25° C. The results of the analysis are set forth inTable 2.

TABLE 2 Salt pH epinephrine malonate 4.34 epinephrine bitartrate 3.75epinephrine fumarate 3.77 epinephrine hemi sulfate 7.14 epinephrinemaleate 4.48

C. pKa

The pKa of epinephrine malonate salt was assessed and compared to otherepinephrine salts. The tests were conducted using Sartorius balances(Model SQP) and a potentiometric titrator (Brand: Methrom, Model No. 905Titrando). 0.17 g of the sample was weighed and transferred into a 50 mLvolumetric flask with the remainder of the volume comprising deonizedwater. The solution was mixed. The solution was titrated with a 0.1mol/L NaOH solution using a pH indicator to indicate the end point. Theresults of the analysis are set forth in Table 3.

TABLE 3 Salt pKa epinephrine malonate 5.47 epinephrine bitartrate 4.20epinephrine fumarate 4.28 epinephrine hemi sulfate undeterminedepinephrine maleate 6.12

D. Partition Coefficient

The partition coefficient (log P) of epinephrine malonate salt wasassessed and compared to other epinephrine salts. The tests wereconducted using Sartorius balances (Model SQP), a Thermo HPLC (UltiMate3000 System, UV Wavelength: 205 nm), and Phenomenex Luna columns (5 μmC18 (2), 4.6×250 mm). The column temperature was 40° C. and theautosampler temperature was room temperature. The injection volume was 5μL.

Mobile Phase A was prepared by weighing 4.0 g tetramethylammoniumbisulfate (MERYER, Batch No. 77957139) and 1.1 sodium 1-heptasulfonate(Admas-beta, Batch No. P1343755), and transferring the materials to aflask. 2 mL of 0.1 mol/L EDTA solution (Brand: Sinopharm ChemicalReagent Co., Ltd., Batch No. 20150410) was added to the flask and thevolume was adjusted to 950 mL using water. The solution was mixed andadjusted to a pH of 3.5 with 0.1N sodium hydroxide solution (Brand:Enox, Batch No. 20161201). Mobile Phase B was prepared using ethanol.The isocratic elution was used in a proportion of A/B of 85/15. The runtime was 8 minutes.

A hydrogen disodium phosphate solution was prepared by weighing 7.1 g ofhydrogen disodium phosphate (Brand: Sinopharm Chemical Reagent Co.,Ltd., Batch No. 20150910). A citric acid solution was prepared byweighing 5.25 g of hydrated citric acid (Brand: General-Reagent, BatchNo. 5949-29-1) and dissolving it in 1000 mL of water. A pH 3.47 buffersolution was prepared by adjusting the pH of the hydrogen disodiumphosphate solution to 3.47 with the citric acid solution. An n-octanolbuffer solution was prepared by mixing 100 mL of n-octanol (Brand:Chinasun Specialty Products Co., Ltd., Batch No. 20160601) and 100 mL ofthe pH 3.47 buffer solution, vibrated for 24 hours, which sat for anhour to separate the n-octanol phase and the pH 3.47 buffer phase.

10 mg of the sample was dissolved in 10 mL of the saturated n-octanolsolution and mixed completely. 10 mL of the saturated pH 3.47 buffersolution was added and vortexed at 3000 r/min for 1 hour. 1 mL ofsolution was pipetted from the n-octanol and pH 3.47 phase after anhour. A standard solution was prepared containing 1 mg/mL of thestandard in diluent. An LOQ solution was prepared from about 0.1% of thestandard solution. An n-octanol phase solution was diluted with 1 mL ofmethanol to test. The pH 3.47 phase solution was injected directly. Thepartition coefficient was calculated using the following formula:

${{lgP} = {lg\frac{Co}{Cw}}},$

wherein Co is the equilibrium concentration of solute in oil phase, andCw is the equilibrium concentration of solute in water phase. Theresults of the partition coefficient analysis are reported in Table 4.

TABLE 4 Salt LogP epinephrine malonate −3.00 epinephrine bitartrate−2.95 epinephrine fumarate −3.00 epinephrine hemi sulfate N/Aepinephrine maleate −3.01

Example 3 Preparation of Pharmaceutical Compositions ComprisingEpinephrine Malonate Salt

Pharmaceutical compositions comprising epinephrine malonate salt andother epinephrine salts were prepared. A sublingual tablet was preparedcomprising 10 mg epinephrine (calculated by epinephrine base). Thecomposition further comprised microcrystalline cellulose (PH-301) as afiller, low-substituted hydroxypropyl cellulose as a disintegrant, andmagnesium stearate as a lubricant. The tablets were prepared by directcompression, using a range of compression forces with the tablet weightaround 80 mg.

Example 4 In-Vitro Permeability of Pharmaceutical Compositions

The in-vitro permeability of the pharmaceutical compositions of Example3 were tested. The tests were conducted using drug transdermal diffusiontest instruments (Brand Huanghai, Model No. RJY-6B), Sartorius balances(Model SQP), an INESA pH meter (Model PHS-3E), a Thermo HPLC (UltiMate3000 System, UV Wavelength: 205 nm), and Phenomenex Luna columns (5 μmC18 (2), 4.6×250 mm). The column temperature was 40° C. and theautosampler temperature was room temperature. The injection volume was 5μL.

Mobile Phase A was prepared by weighing 4.0 g tetramethylammoniumbisulfate (MERYER, Batch No. 77957139) and 1.1 sodium 1-heptasulfonate(Admas-beta, Batch No. P1343755), and transferring the materials to aflask. 2 mL of 0.1 mol/L EDTA solution (Brand: Sinopharm ChemicalReagent Co., Ltd., Batch No. 20150410) was added to the flask and thevolume was adjusted to 950 mL using water. The solution was mixed andadjusted to a pH of 3.5 with 0.1N sodium hydroxide solution (Brand:Enox, Batch No. 20161201). Mobile Phase B was prepared using methanol.The isocratic elution was used in a proportion of A/B of 85/15. The runtime was 10 minutes.

The in vitro diffusion of epinephrine salts were evaluated using Franzcells with an OD of 20 mm and reservoir volume of 7 mL. Dialysismembranes (Spectra/Por® dialysis membranes with 1,000 Da MWCO) were usedto simulate sublingual mucous membrane in the vitro permeability tests.The assay content of the active components was detected in receivingpools. A receptor chamber with a magnetic stirrer was filled withphosphate buffer solution (pH 7.4) as the diffusion medium. The waterbath was set at 37° C., and water was circulated in the Franz cells.

Each tablet was placed at the center of the donor chamber on themembrane at T₀, and 2 mL of the artificial saliva (Brand: Biomart, BrandNo. GL0305) was added to facilitate tablet disintegration anddissolution. Aliquots of 1 mL were withdrawn from the receptor chamberat 10, 30, 60, 90, and 120 min. The volumes withdrawn were replenishedwith fresh medium. Samples were transferred to HPLC vials for HPLCanalysis. The results of the in-vitro permeability analysis are reportedin Table 5.

TABLE 5 Epinephrine salt Diffusion content (%) 120 min epinephrine base10.5 epinephrine hydrochloride 44.0 epinephrine bitartrate 67.8epinephrine malonate 57.5 epinephrine fumarate 54.4 epinephrine hemisulfate 42.7 epinephrine maleate 63.5

Example 5 Stability of Pharmaceutical Compositions

The stability of the pharmaceutical compositions of Example 3 weretested. The stability studies were conducted on packaged epinephrinesalts at 25° C./RH 60% and 40° C./RH 75% conditions, as well as sampleswithout packaging and exposed to light (4500 Lux) for one month. Theappearance, assay content, and related substances were examined at 5, 7,14 and 30 days.

The assay content was tested using Sartorius balances (Model SQP), anINESA pH meter (Model PHS-3E), a Thermo HPLC (UltiMate 3000 System, UVWavelength: 205 nm), and Phenomenex Luna columns (5 μm C18 (2), 4.6×250mm). The column temperature was 40° C., and the autosampler temperaturewas room temperature. The injection volume was 5 μL.

Mobile Phase A was prepared by weighing 4.0 g tetramethylammoniumbisulfate (MERYER, Batch No. 77957139) and 1.1 sodium 1-heptasulfonate(Admas-beta, Batch No. P1343755), and transferring the materials to aflask. 2 mL of 0.1 mol/L EDTA solution (Brand: Sinopharm ChemicalReagent Co., Ltd., Batch No. 20150410) was added to the flask and thevolume was adjusted to 950 mL using water. The solution was mixed andadjusted to a pH of 3.5 with 0.1N sodium hydroxide solution (Brand:Enox, Batch No. 20161201). Mobile Phase B was prepared using methanol.The isocratic elution was used in a proportion of A/B of 85/15. The runtime was 10 minutes.

The assay content was analyzed by dissolving 20 mg of each sample to beexamined in 50 mL of Mobile Phase A (0.4 mg/mL) as assay test solution.The sample was used and tested right after it was ready and wasprotected from light.

The purity was tested using Sartorius balances (Model SQP), an INESA pHmeter (Model PHS-3E), a Thermo HPLC (UltiMate 3000 System, UVWavelength: 205 nm), and PhenomenexSynergi columns (4 μm Polar-RP 80 A250×4.6 mm). The column temperature was 30° C., and the autosamplertemperature was room temperature. The injection volume was 5 μL.

Mobile Phase A was prepared by weighing 1.136 g of potassium dihydrogenorthophosphate (Brand: CNW, Batch No. A1040040) and 1.74 g ofdipotassium hydrogen orthophosphate (Brand: Ourchem, Batch No. 20160219)and transferring into 1000 mL of water. The pH was adjusted to 3.0±0.05with orthophosphoric acid (Brand: Ourchem, Batch No. 4112K060). Thesolution was filtered through a 0.45 μm membrane and degassed. MobilePhase B was prepared using methanol. The run time was 50 minutes. Thegradient set forth in Table 6 was used.

TABLE 6 Time(min) Flow(mL/min) A (%) C (%) 0 0.5 100 0 5 0.5 100 0 200.5 95 5 35 0.5 50 50 37 0.5 100 0 50 0.5 100 0

The purity was analyzed by dissolving 10 mg of each sample to beexamined in 25 mL of Mobile Phase A (0.4 mg/mL) as purity and relatedsubstance test solution. The sample was used and tested right after itwas ready and was protected from light. The appearance, assay content,and related substances at 5, 7, 14 and 30 days under differentconditions are set forth in Tables 7-9.

TABLE 7 Long Term Stability Study at 25 ± 2° C./60% RH ± 5RH EpinephrineTest 0 days 5 days 7 days 14 days 30 days Appearance Off-white Off-whiteOff-white Off-white Off-white powder powder powder powder powder Content(%) 100.00 100.03 99.73 99.84 99.78 Related 0.13 0.14 0.14 0.12 0.14substance (%) Epinephrine Malonate Test 0 days 5 days 7 days 14 days 30days Appearance Off-white Off-white Off-white Off-white Off-white powderpowder powder powder powder Content (%) 100.00 99.94 99.62 98.81 100.64Related 0.01 0.02 0.02 0.05 0.05 substance (%) Epinephrine BitartrateTest 0 days 5 days 7 days 14 days 30 days Appearance Off-white Off-whiteOff-white Off-white Off-white powder powder powder powder powder Content(%) 100.00 100.05 100.83 99.82 100.33 Related 0.08 0.08 0.08 0.09 0.09substance (%) Epinephrine Maleate Test 0 days 5 days 7 days 14 days 30days Appearance Off-white Off-white Off-white Off-white Off-white powderpowder powder powder powder Content (%) 100.00 99.50 99.97 99.43 100.69Related 0.17 0.18 0.17 0.16 0.17 substance (%)

TABLE 8 Accelerated Stability Study at 40 ± 2° C./75% RH ± 5RHEpinephrine Test 0 days 5 days 7 days 14 days 30 days AppearanceOff-white Off-white Off-white Off-white Off-white powder powder powderpowder powder Content (%) 100.00 99.94 100.67 98.97 100.62 Related 0.130.16 0.15 0.17 0.20 substance (%) Epinephrine Malonate Test 0 days 5days 7 days 14 days 30 days Appearance Off-white Off-white Off-whiteOff-white Off-white powder powder powder powder powder Content (%)100.00 100.25 101.64 99.63 99.87 Related 0.01 0.03 0.02 0.08 0.11substance (%) Epinephrine Bitartrate Test 0 days 5 days 7 days 14 days30 days Appearance Off-white Off-white Off-white Off-white Off-whitepowder powder powder powder powder Content (%) 100.00 100.43 100.84100.17 100.96 Related 0.08 0.09 0.09 0.09 0.10 substance (%) EpinephrineMaleate Test 0 days 5 days 7 days 14 days 30 days Appearance Off-whiteOff-white Off-white Off-white Off-white powder powder powder powderpowder Content (%) 100.00 99.30 97.76 99.24 100.19 Related 0.17 0.170.18 0.16 0.16 substance (%)

TABLE 9 Stability Study with Light (4500 Lux) Under Air Epinephrine Test0 days 5 days 7 days 14 days 30 days Appearance Off-white Off-whiteOff-white Off-white Off-white powder powder powder powder powder Content(%) 100.00 100.53 99.27 99.21 98.24 Related 0.13 0.15 0.18 0.18 0.21substance (%) Epinephrine Malonate Test 0 days 5 days 7 days 14 days 30days Appearance Off-white Off-white Off-white Off-white Off-white powderpowder powder powder powder Content (%) 100.00 99.81 98.76 99.83 100.64Related 0.01 0.03 0.03 0.06 0.04 substance (%) Epinephrine BitartrateTest 0 days 5 days 7 days 14 days 30 days Appearance Off-white Off-whiteOff-white Off-white Off-white powder powder powder powder powder Content(%) 100.00 99.71 102.34 100.43 100.39 Related 0.08 0.10 0.10 0.09 0.09substance (%) Epinephrine Maleate Test 0 days 5 days 7 days 14 days 30days Appearance Off-white Off-white Off-white Off-white Off-white powderpowder powder powder powder Content (%) 100.00 99.86 100.61 99.84 100.47Related 0.17 0.18 0.19 0.16 0.17 substance (%)

Example 6 Extended Stability Study of Epinephrine Malonate with NoHumidity

A five month stability study of the epinephrine malonate salt at 30° C.and 40° C. with no humidity was conducted. The epinephrine malonate saltwas packaged to avoid light and humidity. The samples were prepared in abrown glass bottle with the outer packing being an aluminum foil bag,and the samples were stored between layers of dessicant silica gels. Theappearance, residual material, purity, TGA, and DSC were analyzed eachmonth. The results of the 30° C. stability tests are set forth in Table10, and the results of the 40° C. stability tests are set forth in Table11.

TABLE 10 Results of Stability Study at 30° C. Time Residual PointMaterial (Month) Appearance (%) Purity TGA DSC 0 Off-white — 99.96%0.32% Onset: 98.8° C. powder Offset: 104.25° C. 1 Off-white 100.31%99.96% 0.60% Onset: 98.80° C. powder Offset: 103.99° C. 2 Off-white 99.42% 99.96% 0.19% Onset: 99.27° C. powder   Offset: 104.47° C. 3Off-white  99.44% 99.96% 0.90% Onset: 98.72° C. powder   Offset: 104.23°C. 4 Off-white  99.31% 99.73% 0.69% Onset: 99.12° C. powder Offset:103.62° C. 5 Off-white 100.22% 99.96% 0.51% Onset: 98.71° C. powderOffset: 103.92° C.

TABLE 11 Results of Stability Study at 40° C. Time Residual PointMaterial (Month) Appearance (%) Purity TGA DSC 0 Off-white — 99.96%0.32% Onset: 98.8° C. powder Offset: 104.25° C. 1 Off-white  99.59%99.97% 0.16% Onset: 98.89° C. powder Offset: 104.41° C. 2 Off-white100.11% 99.96% 0.13% Onset: 98.78° C. powder Offset: 104.05° C. 3Off-white  98.97% 99.96% 0.51% Onset: 98.69° C. powder Offset: 103.33°C. 5 Off-white  99.68% 99.96% 0.46% Onset: 98.49° C. powder Offset:103.83° C.

Example 7 Stability Study of Epinephrine Malonate at 25° C. in Water

A 120 hour stability study of the epinephrine malonate salt at 25° C.was conducted in water. 20 mg of epinephrine malonate salt was weighedand placed into a 50 mL volumetric flask. The sample was dissolved anddiluted to the volume with water and mixed well. The sample was left inan oven at 25° C., and samples were collected at 0 hours, 24 hours, 48hours, 72 hours, 96 hours, and 120 hours. The diluent (mobile phase)used for the study was prepared by mixing about 1.36 g of potassiumdihydrogen orthophosphate and 1.74 g of dipotassium hydrogenorthophosphate in a 1000 mL volumetric flask, and adjusting the pH to3.0 with orthophosphoric acid. The appearance and purity of the sampleswere tested. The results of the 25° C. stability test in water are setforth in Table 12.

TABLE 12 Time Period Appearance Purity  0 hours Colorless liquid 99.97% 24 hours Colorless liquid 99.79%  48 hours Colorless liquid 99.63%  72hours Colorless liquid 99.51%  96 hours Colorless liquid 99.42% 120hours Colorless liquid 99.34%

Example 8 Degradation Study of Epinephrine Malonate

A degradation study of epinephrine malonate assessing the effect of aciddegradation, alkali degradation, oxidation, and thermal degradation(solid and solution) was conducted. The procedure for the variousconditions is set forth below.

Standard: 20 mg of sample was weighed and dissolved in a 50 mLvolumetric flask, diluted to the required volume with diluents, andmixed well.

Acid Degradation: 20 mg of sample was weighed and placed in a 50 mLvolumetric flask. 2 mL of 2.0 mol/L HCl was added to the flask. Theflask was placed in a water bath at 40° C. for 7 days.

Alkaline Degradation: 20 mg of sample was weighed and placed in a 50 mLvolumetric flask. 2 mL of 0.05 mol/L NaOH was added to the flask. Theflask was stored at room temperature for 24 hours.

Oxidation: 20 mg of sample was weighed and placed in a 50 mL volumetricflask. 2 mL of 10% H₂O₂ was added to the flask. The flask was placed ina water bath at 40° C. for 44 hours.

Thermal Degradation (solution, 80° C.): 20 mg of sample was weighed anddissolved in a 50 mL volumetric flask, diluted to the required volumewith diluents, and mixed well. The flask was placed in a water bath at80° C. for 46 hours.

Thermal Degradation (solid, 80° C.): 120 mg of sample was placed in anoven at 80° C. for 7 days.

The appearance and purity of the samples were test. The results of thedegradation tests are set forth in Table 13.

TABLE 13 Degradation Type Appearance Purity Standard Off-white powder99.89% Acid Degradation Colorless liquid 91.96% Alkaline DegradationBrown liquid 98.68% Oxidation Colorless liquid 97.04% ThermalDegradation (solid) Off-white powder 99.10% Thermal Degradation(solution) Colorless liquid 96.04%

Example 9 Sublingual Pharmaceutical Composition of Epinephrine Malonate

An epinephrine malonate sublingual tablet was prepared as set forthbelow. The pharmaceutical composition is set forth in Table 14.

TABLE 14 Composition % per weight/ Ingredient Unit (mg) weightEpinephrine malonate 31.36*  15.68% Microcrystalline cellulose (CeolusKG 802) 50  25.00% Mannitol (Mannitol Mannogem EZ) 98.64  49.32%Cross-linked polyvinyl 14  7.00% polypyrrolidone (crospovidone) Citricacid (Citric Acid monohydrate) 1  0.50% Silicon dioxide (Cabosil m5p) 2 1.00% Magnesium stearate 3  1.50% Total 200.00 100.00% *1 gram ofepinephrine malonate salt corresponds to 0.638 g of epinephrine freebase. Each tablet comprises 20.0 mg of epinephrine free base.

The tablet was prepared as follows. Epinephrine malonate,microcrystalline cellulose, mannitol, and cross-linked polyvinylpolypyrrolidone were sieved through a 425 micron screen. Citric acid wassieved through an 850 micron screen. The sieved material was transferredto an appropriately sized blending vessel for 500 revolutions. Silicondioxide was sieved through a 425 micron screen. The silicon dioxide wasadded to the blending vessel for 125 revolutions. Magnesium stearate wassieved through a 425 micron screen. Magnesium stearate was added to theblending vessel for 125 revolutions. The tablet was blended bycompressing a 200 mg dose with between 0.5KN and 5KN of force.

Example 10 Stability Testing of Sublingual Pharmaceutical Composition

The stability of the epinephrine malonate sublingual tablet prepared inExample 9 was tested. Tablets were packaged 20 tablets to a bottle, witheach bottle containing a single 1.0 gram silica desiccant and sufficientpolyester coil to prevent tablet movement. The bottles were capped usinga child resistant closure (CRC) with an induction-seal liner and sealed.Bottles were placed in a 40° C. and 25° C. stability chamber. Thestability of the samples was assessed in the initial batch (t=0), after1 week of storage (t=1), and after 4 weeks of storage (t=4). The resultsof the stability study at 25° C. are set forth in Table 15, and theresults of the stability test at 40° C. are set forth in Table 16. Anassay of n=10 was performed at each time point.

TABLE 15 Results of Stability Study at 25° C. Epinephrine Total WtRetention (y − b)/ FBEq LC % % adj. % Time Time Area m = x DF mg/tablet(mg) LC Rel Assay t = 0 8.289 21393253 0.401 500 20.069 20 100.3 0.67101.9 t = 1 8.218 19343265 0.400 500 20.006 20 100.0 0.69 101.7 t = 48.165 3305927 0.401 500 20.055 20 100.3 0.75 100.0

TABLE 16 Results of Stability Study at 40° C. Epinephrine Total WtRetention (y − b)/ FBEq LC % % adj. % Time Time Area m = x DF mg/tablet(mg) LC Rel Assay t = 0 8.289 21393253 0.401 500 20.069 20 100.3 0.67101.9 t = 1 8.218 18861941 0.388 500 19.380 20 96.9 0.66 97.5 t = 48.166 3254834 0.395 500 19.743 20 98.7 0.75 99.9

As illustrated in Tables 15 and 16 herein, the pharmaceuticalcompositions produced unexpected and surprising stability.

Example 11 Dispersion Testing of Sublingual Pharmaceutical Composition

The rate of dispersion of placebo sublingual tablets similar to thoseset forth in Example 9 (i.e., the formulation of Example 9 without drugproduct) was tested after sublingual administration. The placebo tabletshad the same composition as the composition set forth in Example 9 withthe one difference being the epinephrine malonate salt was replaced withadditional diluent (i.e., mannitol). Five human volunteers place onediamond-shaped placebo tablet under their tongue with no water or otherliquid added and measured the time required for the tablet to completelydisperse. Dispersion was determined by feel and by visual confirmation.Dispersion was complete in all five volunteers within 20 to 25 seconds.As illustrated in this Example 11, the pharmaceutical compositionsproduced an unexpected and surprising rate of dispersion.

We claim:
 1. A method for manufacturing an epinephrine malonate salt, said method comprising: adding malonic acid to a solution comprising epinephrine and a solvent; stirring the solution; and precipitating the epinephrine malonate salt out of solution.
 2. The method of claim 1, further comprising filtering the precipitate.
 3. The method of claim 2, further comprising drying the precipitate.
 4. The method of claim 1, wherein malonic acid is added at a ratio of about 0.01:1 to 3:1 relative to epinephrine.
 5. The method of claim 1, wherein the solvent is selected from the group consisting of methanol, ethanol, n-propanol, iso-propanol, n-butanol, sec-butanol, tert-butanol, n-pentanol, 2-methyl-butanol, 3-methyl-butanol, and hexanol.
 6. The method of claim 5, wherein the solvent is ethanol.
 7. A method of treating a patient suffering from an allergic condition, said method comprising: administering a pharmaceutically effective amount of epinephrine malonate to the patient.
 8. The method of claim 7, wherein the epinephrine malonate is administered orally, rectally, intragastrically, topically, intracranially, intranasally, or parenterally.
 9. The method of claim 7, wherein the epinephrine malonate is administered via a buccal or sublingual tablet.
 10. The method of claim 7, wherein the allergic condition is selected from the group consisting of anaphylaxis, asthma, or bronchial asthma.
 11. The method of claim 10, wherein the allergic condition is anaphylaxis. 